April, '10] WASHBURN: EMPOASCA AND PAPAIPEMA 165 



Parasites: We have reared no parasites from Empoasca mali. 



NOTES ON PAPAEPEMA NITELA AND P. CATAPHRACTA 



Papaipema NITELA : Eggs of tliis species, figured on page 153 of 

 our Twelfth Report, were laid about September 15th, 1908. A good 

 many hatched on May 24th and 25th, 1909, the hatching being com- 

 pleted May 29th. In all about one hundred caterpillars emerged. 

 They at once showed the leaf-mining habit by making galleries in the 

 leaves of giant bur-elder seedlings, which happened to be in the cage 

 where they hatched, completely riddling the leaves of these plants 

 (see drawings and photos). The caterpillars in their earlier stages 

 moved like Geometrids. On May 28th about eighty-four larvae from 

 this hatching, which had not had the opportunity to establish them- 

 selves in mines, were placed upon selected bur-elder seedlings. Ac- 

 cording to Doctor Franklin's notes this was done about 5.30 on the 

 above date. At 8 a. m. the next day, May 29th, they had all made quite 

 elaborate galleries in the leaves of these seedlings. On June 2d, 

 after about four days of leaf mining, it was noted that they were 

 working down toward the bases of the leaves, and some had entered 

 the petioles. On June 4th many of the larvae had bored into the 

 stalks — the tallest plants at that time being about five inches high. 

 On July 7th many of these plants had been killed by the borers, and 

 the larvae so deprived of their food plants had entered their second 

 plants. At this date host plants No. 2 were about two feet high, and 

 the galleries therein were about four inches long. On July 22d the 

 larvae were from one to one and a fourth inches long, and the galleries 

 had increased much in extent. 



In one plant two caterpillars were found, and in this one the 

 entrance hole of the lower caterpillar was nine inches from the 

 ground, and that of the upper, thirteen inches from the ground, the 

 galleries in each case being above the entrance holes. 



On August 17th about all the larva which we had reared from eggs 

 had disappeared from the plants. A few of the galleries contained 

 pupae. Therefore, P. nitela larvae may attack two plants in the 

 course of its life, but evidently never more than two. The first moth 

 reared in captivity from the above material, emerged August 24th 

 (one week earlier than last year), and the last one October 1st. Two 

 seasons ' observations indicate that the pupal stage lasts, on an average, 

 twenty-three days. 



P. nitela was reared from the following food plants this season : 

 Nicotiani, lamb's quarters, tomato, giant ragweed, cocklebur, peony, 



